Civil Defence estimates that more than 500 buildings in Christchurch sustained damage in Saturday's earthquake.
That figure includes about 90 damaged buildings in the central business district, although Civil Defence says buildings with fallen chimneys and minor damage are included in the count.
Christchurch City Council says those buildings as well as residences will start being assessed on Sunday by building evaluators.
Red placards will be placed on buildings deemed unsafe and which cannot be entered.
Yellow placards will indicate restricted use and green will show buildings that are safe.
Controller Kevin Locke says tenants will be told the state of their building by the end of the day, and will then be able to start cleaning up once the cordon around the central city is removed.